JP4922752B2 - Perforated support plate - Google Patents

Description

  The present invention relates to a support plate for supporting a wafer, and more particularly to a support plate having a through hole (hereinafter referred to as a “perforated support plate”).

  In recent years, as the demand for integration and small packaging of IC chips becomes strict, development for thinning wafers has attracted attention. When the wafer is thinned to some extent, the entire surface is warped as the surface strength is reduced, and support by another support member is required when handling the wafer. For this reason, a wafer to be thinned to some extent is handled after a support plate made of glass or iron-nickel alloy or the like as the support member is attached in advance to reinforce the surface strength. Bonding of the support plate to the wafer is performed by interposing an adhesive substance (for example, an adhesive) between the wafer and the support plate. The support plate is peeled from the wafer by dissolving the substance with a solution. This solution is guided to the substance by immersing the wafer and the support plate in the solution.

  Nowadays, in order to react the solution with the substance in a short time, the support plate is provided with a number of minute through holes in the thickness direction of the support plate that lead the solution to the wafer. Support plates are widely used. In some cases, the through-holes have a structure in which a glass substance is left in a non-penetrated state so that it can be penetrated later, particularly in a glass support plate. Such a large number of through holes are provided in the support plate at a substantially uniform high density over the entire range where the wafers are bonded together.

The configuration of an iron-nickel alloy support plate having a through hole is disclosed in Patent Document 1.
JP 2005-191550 A

In order to reinforce the surface strength of the wafer to be thinned, a glass support plate having a thickness of 0.7 mm is used.
In the 0.7 mm-thick glass support plate having a large number of through-holes through which the solution is passed, all of the through-holes are formed on the edge of the perforated support plate and the vicinity thereof. Are substantially uniformly provided at a high density in almost all regions where the mark is left. For this reason, the solution can be efficiently guided to the entire bonding surface with the wafer through the through-hole, and the adhesive substance interposed between the wafer and the perforated support plate can be quickly reacted to react with the wafer. The perforated support plate can be peeled off in a short time.

  However, in recent years, the diameter of the wafer has been increased to 300 mm or more, and accordingly, the diameter of the perforated support plate is also required to be increased to 300 mm or more. The perforated support plate lacks the constituent material of the base material by the amount of the through-hole and is less rigid than the ordinary support plate without the through-hole for allowing the solution to pass therethrough. With a small-diameter perforated support plate so far, a certain level of strength could be ensured. However, with a perforated support plate having a diameter of 300 mm or more, 0.7 mm thick, A certain level of strength is not ensured, and bending occurs. That is, the conventional perforated support plate has a problem that when the diameter is increased, the deflection occurs, and the deflection of the wafer cannot be suppressed.

  In order to avoid the above problem, conventionally, a 1 mm-thick glass plate-like substrate thinned to 0.8 mm was used as a large-diameter perforated support plate having a diameter of 300 mm or more. However, in such a case, processing such as thinly cutting a 1 mm-thick plate-like substrate until it becomes 0.8 mm thick is necessary, and a 0.7 mm-thick glass plate-like substrate is used as it is. There was a problem that the number of work steps increased compared to the case. In addition, the thickness of the support plate having a large diameter of 300 mm or more is different from that of the support plate having a small diameter. Therefore, it is necessary to provide components corresponding to each thickness so that a perforated support plate having a different thickness can be handled for each device (for example, a bonding device, a peeling device, etc.) that handles a perforated port plate. There have been problems such as an increase in the number of parts and an increase in the size of the apparatus.

  The present invention has been made in view of the above problems, and an object thereof is to provide a perforated support plate having increased rigidity.

In order to solve the above problems, the present invention is configured as follows.
A perforated support plate for supporting a surface of a wafer with an adhesive layer interposed therebetween, and a reinforcing portion for preventing deflection, which is a region having no holes for preventing deflection formed of a line of a geometric pattern, formed on a plate-like substrate. The geometric pattern includes a plurality of concentric circles, radially extending lines, or repetition of the same figure.

Also, a perforated support plate for supporting the wafer with the adhesive layer interposed therebetween,
A reinforcing portion for preventing bending, which is a region without a hole for preventing bending formed of a line of a geometric pattern, formed on a plate-like substrate is provided, and the line width of the geometric pattern is 1 mm or less.

The perforated support plate may further be provided with an unopened suction area corresponding to a vacuum suction device.
The perforated support plate preferably has a diameter of about 300 mm and a thickness of 0.7 mm or less.

In the present invention, since the reinforcing portion for preventing deflection is provided, the rigidity of the perforated support plate can be increased.
In addition, in the case where the reinforcing portion for preventing bending is provided on the plate-like base material as a region having no holes for preventing bending made of a geometric pattern line, the thickness of the perforated support plate is set to the thickness of the plate-like base material. Can be adapted to

  In addition, when the geometric pattern is constituted by a plurality of concentric circles, radially extending lines, or repetition of the same figure, the surface strength can be efficiently increased over a wide range of the perforated support plate.

  Further, by setting the line width of the geometric pattern to 1 mm or less, the difference between the pitch of the through holes and the pitch of the adjacent through holes via the reinforcing portion for preventing deflection is narrowed. Therefore, the increase in the peeling time between the wafer and the perforated support plate due to the provision of the reinforcing portion for preventing the bending can be suppressed to a small level.

Further, by providing the non-opening area for adsorption, the adsorptivity when using a vacuum adsorption apparatus is improved.
In particular, in a perforated support plate having a diameter of 300 mm or more and a thickness of 0.7 mm, the occurrence of bending can be suppressed by increasing the rigidity, and the usability as a perforated support plate is increased.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG.1 and FIG.2 is explanatory drawing of the perforated support plate of this invention in 1st embodiment. FIG. 1A is a perspective view of the perforated support plate, and FIG. 1B is a plan view of the perforated support plate. 2A is an enlarged view of a dotted line A portion in FIG. 1B, and FIG. 2B is a cross-sectional view taken along line BB ′ of FIG.

  A perforated support plate 1 shown in FIGS. 1 (a) and 1 (b) is formed on a plate-like substrate 10 obtained by processing a plate-like glass material having a thickness of 0.7 mm into a circle having a diameter of 300 mm. A number of through-holes (shown by dots in the figure) 12 are opened.

  The through-hole 12 is formed by removing the glass material in the thickness direction from one or both sides of the plate-like substrate 10 by etching or the like. The through-hole 12 is used as a passage for guiding the liquid toward the surface (the surface of the plate-like substrate 10 shown in FIG. 5B) on the side to be bonded to the wafer (not shown). As this liquid, the wafer and the plate-like substrate 10 are bonded together by being interposed between the wafer and the plate-like substrate 10 (on the surface of the plate-like substrate 10 shown in FIG. 5B). A solution of an adhesive member (not shown) such as an adhesive is used. Since this solution is used when the plate-like substrate 10 is peeled after the wafer is thinned, the through hole 12 only needs to be penetrated when the plate-like substrate 10 is peeled off. In the following description, the through-hole 12 is a hole penetrating the plate-like substrate 10 in the thickness direction, but leaves a part of the glass substance so that the plate-like substrate can be penetrated immediately before peeling. May be left unpenetrated.

In the perforated support plate 1, the plate-like base material 10 has a structure that does not have a through-hole in a line portion 14 of a geometric pattern formed by repeating circles.
A more detailed structure of the geometric pattern line portion 14 is as shown in the partially enlarged view of FIG. 2A and the cross-sectional view of FIG. That is, as shown in FIG. 2 (a), a large number of through holes (black dots in FIG. 2 (a)) 12 are provided on the plate-like substrate 10 with a substantially equal density. The through-hole is not provided in the part of the pattern line (white thick line in FIG. 1A) 14. Further, as shown in FIG. 4B, in the region 12 ′, a large number of through holes 12 penetrating from the upper surface 10A to the lower surface 10B (thickness direction) of the plate-like base material 10 are provided. The glass material is completely removed at the position of the hole 12 (the portion indicated by black vertical stripes in FIG. 5B), but there is no through hole in the line portion 14 of the geometric pattern due to repeated circles. The glass material constituting the plate-like substrate 10 remains as it is.

  Here, an example of the dimension of the line portion 14 of the geometric pattern and the dimension of the through hole 12 is as follows. That is, the geometric pattern line is about 1 mm wide, the inner diameter of the circle is 29 mm, and the outer diameter of the circle is 31 mm, and the through holes 12 are provided with a diameter of about 0.4 mm and a pitch of about 0.6 mm. The line of the geometric pattern has a predetermined line width as described above. As shown in FIG. 2A, the region where the through hole 12 is provided is divided into islands at the portion 14 thereof. To do.

  In the above numerical configuration, even a 300 mm diameter and 0.7 mm thick glass perforated plate base material does not bend. This is because the glass material remaining in the line portion 14 of the geometric pattern is integrated with the glass material surrounding each through-hole 12 and acts to increase the rigidity of the plate-like base material 10. This is because it functions as a reinforcing portion that prevents the bending of the material 10. Therefore, in this specification, the region of the line portion 14 of the geometric pattern formed on the plate-like base material 10 is referred to as a “reinforcing portion” or “a region without a deflection preventing hole”.

  Note that the size and arrangement of the diameters of the through holes 12 are closely related to the bonding accuracy between the wafer and the plate-like substrate 10 and the peeling time when the plate-like substrate 10 is peeled from the wafer. Therefore, when providing a reinforcement part, it is necessary to pay attention so as not to extend the peeling time while maintaining a required bending prevention effect. At the present stage, it has been found that the line width of the reinforcing portion may be set to 1 mm or less in order to suppress the extension of the peeling time.

  In addition, since the said reinforcement part and the through-hole are formed in the sheet-like base material 10 here, both can be formed simultaneously. That is, a resist mask in which a position where the through-hole 12 is formed is opened and a region serving as a reinforcing portion is not opened is laminated on a plate-like substrate through a photolithography process, and the above-mentioned is performed by anisotropic etching such as dry etching. It can be formed by opening a through hole in the plate-like substrate through the opening and then removing the resist mask on the plate-like substrate. In this case, an area of 1 mm or less, which is indicated by a line of the geometric pattern, remaining at the position where the resist mask was last removed becomes a reinforcing portion.

  In the above description, the reinforcing portion formed on the plate-like base material, that is, the “region without a hole for bending prevention” has been described. However, the “reinforcing portion” is not limited to the “region without a hole for bending prevention”, but in other forms. May be provided. For example, a separate reinforcing plate provided with an opening or a plurality of through holes outside the range indicated by the lines of the geometric pattern is prepared, and this reinforcing plate is made of a glass plate having through holes in the entire surface. Even if it is provided by bonding to a shaped substrate, the rigidity can be increased.

As described above, in the first embodiment, the portion of the circular geometric pattern line is not penetrated in the glass plate-like base material, and the portion is used as the reinforcing portion.
As described above, by arranging the reinforcing portion in a circular geometric pattern on the plate-like base material, the surface strength can be efficiently increased over a wide range.

  Moreover, the rigidity of the whole surface of the plate-like substrate can be increased by providing the reinforcing portion of the circular geometric pattern over the entire surface of the plate-like substrate. In the plate-like substrate made of glass having a diameter of 300 mm and a thickness of 0.7 mm, it becomes possible to prevent the occurrence of bending, and the usability to the attaching device and the peeling device has been improved. In this case, since the thickness is the same as the 0.7 mm thickness smaller than the 300 mm diameter, for example, without significantly changing the configuration in the bonding apparatus, the peeling apparatus, etc., and without significantly increasing the number of parts. It becomes possible to handle the small-diameter and large-diameter perforated support plates in the same manner.

  In addition, the plate-like base material itself having a reinforcing portion, that is, the one having the “deflection-preventing hole-free region” has the same thickness as the plate-like base material and the reinforcing portion. The support plate can be made the same thickness as the plate-like substrate.

  Further, by setting the line width of the geometric pattern to 1 mm or less, the difference between the pitch of the through holes and the pitch of the adjacent through holes via the reinforcing portion for preventing deflection is narrowed. Therefore, the increase in the peeling time between the wafer and the perforated support plate due to the provision of the reinforcing portion for preventing the bending can be suppressed to a small level.

In addition, since the no-deflection hole-free region is formed when the through-hole is formed, the overall man-hour for manufacturing the perforated support plate does not increase.
(Second embodiment)
In the second embodiment, a perforated support plate used in a suction device that holds a single surface by vacuum suction will be described.

  FIG. 3A is a plan view of a perforated support plate according to the second embodiment, and FIG. 3B is an enlarged view of a dotted line C portion in FIG. In addition, in each figure (a) and (b), the same number was attached | subjected to the thing of the same structure as FIG.1 (b) or FIG.2 (a).

Hereinafter, differences from the first embodiment will be described in detail.
The perforated support plate 2 in FIGS. 3A and 3B is similar to the one shown in the first embodiment in that a 0.7 mm-thick glass plate-like substrate 10 is circular with a diameter of 300 mm. A plurality of through-holes 12 having a diameter of about 0.4 mm are formed at a high density on the entire surface.

  The plate-like base material 10 is further formed with an unopened area 20 for adsorption. The non-opening area 20 for suction is configured so that a high negative pressure is applied by evacuation from a vacuum suction apparatus including a vacuum chuck or the like. Therefore, the suction non-opening region 20 is provided in accordance with the position of the suction groove or hole provided in the vacuum suction device, and the arrangement and shape are determined according to the design of the vacuum suction device. . The non-opening area 20 for adsorption is arranged as shown by a plurality of concentric circles as shown in FIG. In addition, the adsorption | suction non-opening area | region 20 should just have the structure of the non-penetrating state in the area | region so that air may not escape up and down of the plate-shaped base material 10. FIG. For example, a structure in which both the upper and lower surfaces are closed, a structure having a shielding part in a part in the thickness direction of the plate-like substrate, and the like. As described above, the suction non-opening region 20 does not have a through hole, but is completely different from the “reinforcing portion” in terms of the position to be formed, the area to be formed, the function, and the specific structure.

  In terms of the area to be formed, for example, the suction non-opening region 20 and the deflection preventing holeless region 14 have different line widths. In FIG. 2B, the line width of the deflection preventing holeless region 14 is narrower than the line width of the suction non-opening region 20. In order to compare the line widths, numerical data is given as an example as follows. That is, each through-hole 12 is provided with a diameter of about 0.4 mm and a pitch of about 0.6 mm, and the geometric pattern line 14 by repeating the circle is about 0.7 mm wide, the inner diameter of the circle is 29.5 mm, and the outside of the circle. It is arranged with a diameter of 30 mm. And the line of the concentric circle which comprises the said non-opening area | region 20 for adsorption | suction is each provided about 1 mm wide. However, since the suction non-opening region 20 needs to be provided in a size that covers the suction groove or suction hole of the vacuum suction device, the line width should be at least 0.5 mm or more in accordance with the suction groove or suction hole of the vacuum suction device. It is preferable to take a wide range.

  In the second embodiment, a portion (common region) where the suction non-opening region 20 and the deflection preventing holeless region 14 overlap is generated. In this common region, it is necessary to achieve the two purposes of reinforcing the plate-like substrate without reducing the adsorptivity by the vacuum suction device. Therefore, the common area is configured as the deflection preventing holeless area 14.

  The suction non-opening region 20 and the deflection preventing hole-free region 14 can be formed simultaneously with the formation process of the through-hole 12 as follows, for example. That is, a resist mask in which the position where the through-hole 12 is formed is opened and the position corresponding to the non-opening area 20 for adsorption and the area 14 without a hole for bending prevention is not opened is formed through a photolithography process. It can be formed by laminating on the material 10, making a through hole through the opening in the plate-like substrate 10 by anisotropic etching such as dry etching, and then removing the resist mask on the plate-like substrate 10. . In this case, of the region remaining at the position where the resist mask was finally removed, the region of 0.7 mm or less indicated by the geometric pattern line is the non-deflection holeless region 14 and is indicated by the concentric circle line, for example. An area of 1 mm or more becomes an unopened area 20 for suction.

As described above, in the second embodiment, the plate-like base material shown in the first embodiment is further provided with the adsorption unopened region 20. Since the perforated support plate in the second embodiment is provided with the suction non-opening region 20, the adsorptivity is improved as compared with the perforated support plate 1 shown in the first embodiment. . In particular, the region 14 without bending for preventing deflection includes a region (common region) that overlaps with the non-opening region 20 for adsorption, but the common region does not constitute a through hole. The same effect as the support plate 1 without a hole in the form of can be obtained.
(Third embodiment)
In the third embodiment, a reinforcing portion (particularly a region without a deflection preventing hole) configured in the perforated support plate of the present invention shown in the first and second embodiments, and an unopened portion for suction The modification of an area | region is shown. However, although not specifically described below, it is assumed that each of the “deflection prevention hole-free region” and the “adsorption non-opening region” is provided under the conditions described in the second embodiment.

FIG. 4 and FIG. 5 are modifications of the circular geometric pattern lines of the reinforcing portion shown in the first embodiment (or the region without a deflection preventing hole shown in the second embodiment).
FIG. 4 shows an example in which the circular geometric pattern line is changed to a polygonal geometric pattern line, and the reinforcing part (or the deflection preventing part) is formed by the geometric pattern line 30 having a hexagonal repeating pattern. Non-hole region).

  FIG. 5 shows an example in which the circular geometric pattern line is changed to a geometric pattern line formed by a combination of a plurality of concentric circles, and the reinforcing portion (or for preventing deflection) by six concentric circular lines 40 having different radii. Non-hole region).

  6 to 8 are examples in which the shape of the concentric circles of the unopened region for suction shown in the second embodiment is modified. Each of them is deformed in accordance with the positions of the suction grooves and holes formed in the vacuum suction device.

FIG. 6 shows an example in which the non-opening area for adsorption is provided in an island shape. Here, as shown in the figure, oval suction non-opening regions 50 are provided at four positions equidistant from the center.
FIG. 7 shows an example in which the non-opening area for adsorption is provided as two strip-like lines 60 that are orthogonal to each other.

FIG. 8 shows an example in which the suction non-opening region is provided with an island shape at the center and a concentric line 70 at the outer periphery.
In addition, the pattern of the reinforcement part (or area | region without a hole for bending prevention) shown above is an example. Therefore, you may comprise the pattern of the said reinforcement part (or area | region without a hole for bending prevention) with the line of another geometric pattern. For example, the geometric pattern line may be formed by using only one circle or polygon.

  The shape of the non-opening area for adsorption shown above is also an example. Therefore, the shape of the non-opening area for suction may be appropriately changed in accordance with the suction groove or hole configured in the vacuum suction apparatus.

  In addition, in the perforated support plate used in the suction device of the type that holds one surface by vacuum suction, the above-described pattern of the non-deflection hole and the above-mentioned pattern and shape are arbitrarily combined. The shape of the unopened region for adsorption may be formed.

  As described above, in the third embodiment, the reinforcing portion can be configured with various patterns. Therefore, an optimal pattern can be selected from the material and design of the plate-like substrate. In addition, since various patterns and shapes can be combined to form the pattern of the non-deflection hole-free area and the shape of the non-opening area for adsorption, a perforated support plate with high adsorption and rigidity can be used as a vacuum adsorption device. It can be appropriately selected depending on the case.

  Further, the effects shown in the first and second embodiments can also be obtained.

It is explanatory drawing of the perforated support plate of this invention in 1st embodiment. It is the elements on larger scale of the said perforated support plate. It is explanatory drawing of the perforated support plate of this invention in 2nd embodiment. It is a figure which shows the modification of the line of the geometric pattern in the area | region without a hole for bending prevention (the 1). It is a figure which shows the modification of the line of the geometric pattern in the area | region without a hole for bending prevention (the 2). It is a figure which shows the modification of the shape of the non-opening area | region for adsorption | suction (the 1). It is a figure which shows the modification of the shape of the non-opening area | region for adsorption | suction (the 2). It is a figure which shows the modification of the shape of the non-opening area | region for adsorption | suction (the 3).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Perforated support plate 10 Glass plate-shaped base material 12 Through-hole 14 Geometric pattern line part

Claims (4)

A perforated support plate for supporting a wafer with a bonding layer interposed therebetween,
Provided with a reinforcing portion for preventing deflection, which is a region without a hole for preventing deflection formed of a line of a geometric pattern, formed on a plate-like substrate ,
The geometric pattern is constituted by a plurality of concentric circles, radially extending lines, or repetition of the same figure.
Perforated support plate characterized by that. A perforated support plate for supporting a wafer with a bonding layer interposed therebetween,
Provided with a reinforcing portion for preventing deflection, which is a region without a hole for preventing deflection formed of a line of a geometric pattern, formed on a plate-like substrate,
The line width of the geometric pattern is 1 mm or less,
Perforated support plate, characterized in that. The support plate has an unopened area for suction;
The perforated support plate according to claim 1 or 2, wherein the support plate is perforated. The diameter is approximately 300 mm and the thickness is 0.7 mm or less.
A perforated support plate according to any one of claims 1 to 3.